Features

• Uses Tiny Capacitors and Inductor
• High Frequency Operation: Up to 4MHz
• Low R_DS(ON) Internal Switches: 0.110Ω
• High Efficiency: Up to 96%
• Stable with Ceramic Capacitors
• Current Mode Operation for Excellent Line and Load Transient Response
• Short-Circuit Protected
• Low Dropout Operation: 100% Duty Cycle
• Low Shutdown Current: I_Q ≤ 1μA
• Low Quiescent Current: 60μA
• Output Voltages from 0.8V to 5V
• Selectable Burst Mode® Operation
• Sychronizable to External Clock
• Small 3mm × 3mm, 10-Lead DFN Package

Typical Application

Description

The LTC®3568 is a constant frequency, synchronous step- down DC/DC converter. Intended for medium power applications, it operates from a 2.5V to 5.5V input voltage range and has a user configurable operating frequency up to 4MHz, allowing the use of tiny, low cost capacitors and inductors 2mm or less in height. The output voltage is adjustable from 0.8V to 5V. Internal sychronous 0.11Ω power switches with 2.4A peak current ratings provide high efficiency. The LTC3568’s current mode architecture and external compensation allow the transient response to be optimized over a wide range of loads and output capacitors.

The LTC3568 can be configured for automatic power saving Burst Mode operation to reduce gate charge losses when the load current drops below the level required for continuous operation. For reduced noise and RF interference, the SYNC/MODE pin can be configured to skip pulses or provide forced continuous operation.

To further maximize battery life, the P-channel MOSFET is turned on continuously in dropout (100% duty cycle) with a low quiescent current of 60μA. In shutdown, the device draws <1μA.